Olefins, especially light olefins including ethylene and propylene, are valuable hydrocarbon products. They are useful for preparing a wide variety of end products, including ethylene oxide, propylene oxide, ethylbenzene, acetone, phenol, polyethylene, polypropylene, other polymers, and other petrochemical products. Even though their prices have been fluctuated over time, their demands in the industry have still been continuously growing.
To serve the industrial needs, many methods have been used to produce olefins. However, it is typically more economically attractive to produce olefins from lower valued feedstock such as paraffin. A conventional method for converting parafins to olefins is thermal cracking. This is a highly energy intensive method and product selectivity is difficult to be adjusted and controlled. Catalytic cracking is a later developed method. With appropriate catalytic materials, generally zeolite-based materials, hydrocarbon cracking can occur at less severe operating condition.
Several improvements on catalytic cracking have been studied and disclosed. For example, U.S. Pat. No. 8,933,286 B2 disclosed a catalytic cracking process using a zeolite catalyst modified with nickel. The process can be operated at milder operating condition. However, significant amount of by-products including methane and C5+ hydrocarbons can be observed and there was no indication regarding stability of the catalyst.
U.S. Pat. No. 8,198,498 B2 disclosed a carbon nanotube catalyst coated with metal oxides for using in hydrocarbon cracking process. The process is still highly energy intensive because it has to be carried out at quite high temperatures, and preferably with addition of steam to the feed stream, in order to achieve improved yield of the desirable olefins product.
It is, therefore, an object of the present invention to provide a hydrocarbon conversion process overcoming drawbacks of the prior art. In particular, a process shall be provided allowing the conversion of a hydrocarbon feed comprising saturated hydrocarbon compounds to olefin products, i.e. less saturated hydrocarbon products. It is further object to provide a process allowing the above conversion at mild conditions, in particular at comparatively low temperatures. Furthermore, it is an object to provide a process allowing the conversion of olefins with high selectivity, i.e. by avoiding undesired by-products, such as methane or hydrocarbons having 5 or more carbon atoms.